Do not scavenge bike parts, you could very easily be arrested. Just because you may have seen other instances where it has been done seemingly without recourse, don't think it definitely won't happen to you.
If you do find that someone has locked your bike with an extra lock, phone the police switchboard and ask for your local station. Let them know this has happened and that you think the intention is to steal your bike. Tell them you are going to cut off the offending lock and ask for a reference number from whoever you speak to. That way, if plod do approach you and ask why you are cutting the lock, you can explain it to them, give them the reference number (preferably a CAD number) and all SHOULD be ok. Also, keep plenty of photos of your bike and any serial numbers (a full list of components is also handy).
Rest assured people do get arrested for these kind of things. I (during my term with the MPS) arrested two yoots in Clapham for hanging around the locked bikes behind Clapham Common Tube Station. One had a bike lock but no bike and the other had bolt cutters, both knew each other. Both were arrested for going equipped to steal. Don't let it happen to you.
Do not scavenge bike parts, you could very easily be arrested. Just because you may have seen other instances where it has been done seemingly without recourse, don't think it definitely won't happen to you.
If you do find that someone has locked your bike with an extra lock, phone the police switchboard and ask for your local station. Let them know this has happened and that you think the intention is to steal your bike. Tell them you are going to cut off the offending lock and ask for a reference number from whoever you speak to. That way, if plod do approach you and ask why you are cutting the lock, you can explain it to them, give them the reference number (preferably a CAD number) and all SHOULD be ok. Also, keep plenty of photos of your bike and any serial numbers (a full list of components is also handy).
Rest assured people do get arrested for these kind of things. I (during my term with the MPS) arrested two yoots in Clapham for hanging around the locked bikes behind Clapham Common Tube Station. One had a bike lock but no bike and the other had bolt cutters, both knew each other. Both were arrested for going equipped to steal. Don't let it happen to you.